Voltage multiplication systems



March 31, 1959 R. J. CALLENDER 2,880,385

VOLTAGE MULTIPLICATION SYSTEMS Filed March 29, 1952 70 7550 42F'.j C

ll 24 g 2 if ,26 F 3 27 T T 7 INVENTOR Passe J. Ca/Mnder- BY W 42% ATT()RNEY United States Patent-O VOLTAGE MULTIPLICATION SYSTEMS ''Russell J.Callender, St. Paul, Minn.- Application Marcl1 29, 1952, Serial No.279,339 6 Claims. (Cl. 321 -2 This invention relates to voltagemultiplication systems,

1 and pertains more particularly to an improved system of this generalcharacter having a high degree ofv voltage regulation for various loadconditions.

. In a number of electronic circuit applications it is necessary toprovide a relatively high voltage output fr'om a given lower voltagesource over a rangefot different load conditions. In conventionaloscillator-multiplier. 'systerns of this type a high output voltagecarries with it"the I concomitant disadvantage of having large swings inoutput voltage for thevarious load changes to which'the now employedsystems are subjected. In someinstances such swings are intolerable, forobviously relatively large ,swings in outputvoltage causecorrespon'dingswings'in output current. One example where large voltageand urrent? changes are exceedingly detrimental is in telew visionreceivers, for in such installations picturetube voltages of the orderof 30,000 volts are encountered and deviations in this picture voltagewill of course adversely affect the picture tube beam. current andconsequently I lithe focusing of the picture itself.

Accordingly, an object of the instant invention isto provide a voltagemultiplier system that will be extremely stable in voltage output forvarious load conditions.

Another object of the invention is to provide a 'system,

as above mentioned, that will have a relatively out- .putcurrent at thehigh operating voltagesfonwhich it is designed.

. Another object of this invention is to eliminate the tickler or'feed.back coil of conventional generator systems of this general character,thereby eliminating any danger of arcing between the highvoltage'output'fcoil and the prior art tickler coil or the circuitryassociated therewith, these latterelements being generally lo w'voltfagecomponents. i V i a, Another object of the invention is to provide anovel grid shunt arrangement, adjustable to keep grid to ground lvoltage within controlled limits and to preventeiffectually insulationbreak downs. between the various parts com- A prising the oscillatortube.

- A furtherfeature of the invention resides in the physical positioningand arrangement of the component' parts of my systemwhereby any coronadischarge. efiec't is effectively minimized for the high voltagesinvolved.

Still another feature of the instant invention resides in the attainmentof a high output voltage at the general magnitude ordinarily obtainedwith a tripler circuit, the

invention employing only a, doubler circuit.

; Yet. another purpose, of the invention is to provide tunable means forheating the cathodes of the diodes used in the doubler portion of myoverall system.

For a more complete understanding of the nature and scope of myinvention reference can be had to the fol- I lowing detaileddescription, taken together with the accompanying drawing, in which:

Figure 1 is an elevational view in section of the chassis and thephysical arrangement of the salient parts of my 2,880,385 Patented Mar.31, 1959 inventionin relation thereto, the view being taken in thedirection of line 11.of Figure 2;

, Figure 2 is a view taken in the direction of l ne 22 ofjEigure 1 withthe chassis cover removed; and

Figure 3 is diagrammatically illustrative of the circuitry usedincarrying out the concepts of my invention.

in'Figure 3. 'plifier' tube 10,'in which the cathode 12' and the sup-For a more facile understanding of the invention, it is thoughtdesirable to first describe the circuit'pictured In this figure thereisshown a power ampressor grid 14 are grounded in conventional manner.

0 Whereas, I have shown only one tube 10, it will of course beunderstood that more than one tube may be utilized when desiredjthetubes then being'con'ne'cted in parallel with suitable resistorstherebetween for operational stab'ilization. For instance, I havesuccessfully operated my system when using two 6BQ6-GT tubes. The screengrid'16 is connected to a voltage supply of approximately 1 150JvoltsDC; as shown, this grid 16 is connected to the high side ofth'e Blpowersupply source 17 having a resistance 18 of about 8,500 ohms incircuittherewith to provide the 150 volts screen voltage when the source 18 isa potential of roughly 400 volts DC. or less.

Theplate 20 has in circuit with it a parallel resonant L-C circuitcomprising a low inductance coil 22 and a I variable high capacitancecondenser 24. Asa suggested frequcn'cy, the coil 22 and condenser 24should be tunable'to a resonant frequency in the neighborhood of200kilocycles. 'ln circuit with the plate 20 and the 'L-C circuit 22,24'is a choke coil 26 of approximately a 2.5 millihenries for thepurpose of choking out A.C.

pulsations in this D.C. plate circuit. In order to rid the plate circuitof undesired A .C. components, a condenser 27 in the neighborhood of 0.1mt. is connected so as to f pass theseA.C. currents to ground.Similarly, a con- -This coil 30 has'a low distributive capacitance andof tween the two coils 22 and 30.

course influences to a certain extent the setting of the condenser 24,for there is a mutual inductive effect be It is not believed necessaryto separate or classify the effects of the resonance producingcomponents22, 24 and 30, it only being necessary to appreciate thatthese elements are tunable to a particular resonantfrequency, assumed tobe 200 kilocycles in this discussion. However, it should probably bestated at this point that with a primary voltage of 250 volts A.C.impressed upon the coil 22, the coil 30 should be so designed to producea secondary voltage of approximately 15,000 volts A.C.. of a pair. ofterminals 31. In other words, the coils 22 and 30 serve as a step-uptransformer, and in order to produce the proper phase relation ingenerating the desired oscillations-these coils are oppositely wound asdenoted in the drawing.

One end 32 of the coil 30 leads directly to the doubler portion of thesystem (yet to be described), and the other end 34 is connected to thegrid 29 of the tube 10. Also itance of 2200 'mmf. 'gridresi'stance 40having a value of from 150,000 to connected to the end 34 of the coil 30is a variable powdered iron core coil 36 having an inductance rangingfrom 1.0 millihenry to 5.0 millihenries, and between the coil 36 andground is a grid condenser 38 having a capac- Paralleling the condenser38" is a 175,000 ohms. The iron core coil 36, the capacitor 38 and theresistor 40 serve as a shuntfo radju'sting the 3 amount of bias on thecontrol grid 29, as will hereinafter be made clearer in connection withthe operational sequence of the system. The condenser 38 also serves asa by-pass condenser for the grid 28 to ground through the variablereactance of the coil 36.

The circuitry thus far described may be referred to as the oscillatorcircuit and for convenience of reference this circuit is given theletter A. As will be seen from a continued reference to Figure 3, thedoubler portion of the multiplier system bears the letter B, and willnow be described in detail. The ungrounded side of the doubler B is incircuit with the coil 30 and has contained therein a condenser 42 in theorder of 1500 mfd.

In circuit with the condenser 42 and ground is a halfwave rectifier 44,such as a diode 1B3-GT tube. The cathode 46 of the tube 44 is heated byan auxiliary circuit comprising an inductance 48 and capacitance 50adjustable over a frequency range in the neighborhood of the 200kilocycles suggested as the operating frequency or whatever systemfrequency is selected. The inductance 48 is tapped at 47 and desirablythere is placed a small current limiting resistor 49 in circuit with thetapped portion of the inductance 48 and the cathode 46. It will beobserved that it is the plate 52 of this tube that is connected toground.

A similar diode 54 has its plate 56 connected to the condenser 42 andits cathode 58 is heated in the same fashion employed for the rectifiertube 44, there being a similar inductance 60 with a tap 59, a resistor61 and capacitance 62 in circuit with the cathode 12. The juncture ofthe inductance 60 and capacitance 62 opposite the cathode 58 isconnected with a condenser 64 of approximately 500 nnmfd. which is inturn connected to ground.

A pair of terminals 66 is made available for the connection to anyappropriate load. Since my system is particularly designed for supplyingthe beam current for television picture tubes, a load of approximately88 or even more, when previously delivering a full load voltage-of31,000 volts. Also, a relatively large output current (in theneighborhod of 200-800 micro ampere) is to be expected under the abovereferred to full load conditions. It should of course be understood thatthe various values mentioned in the course of this description arerepresentative and that persons skilled in the art may wish to vary theconstants and variables herein mentioned to'suit the particular designof installation involved.

The operation of my system will now be briefly reviewed. 'The particularsource 17 is selected so as to deliver 180 milliamperes at 325 volts.Then the condenser 24 is adjusted so that resonance is produced in theplate circuit, such resonant condition being observable when the voltageat 31 is a maximum. After this, the iron core coil 36 is adjusted forthe proper grid voltage at the control grid 29. Such a grid voltageshould be approximately negative 325 volts, plus or minus 50 volts asmeasu'red from the grid 29 to ground. However, it is voltage has beenmentioned as negative 325 plus or minus 50 volts, this represents anoptimum value which is susceptible to considerable variation. It isbelieved that the elements 36, 38 and 40 act as a shunt which not onlyserves as a means for initially setting the grid voltage for the propervalue but thereafter during the functioning of the system cooperates inthe stabilizing of the output voltage at the terminals 66 for thevarious encountered load conditions.

The doubler circuit B requires that the condensers 50 and 62 be adjustedto produce a tuning condition with the respective coils 48 and 60 thatwill result in the requisite heat in the cathodes 46 and 48. This is allthat need be done, for the cathodes 46 and 58 will upon becoming heated,emit the necessary electrons to produce electron flow to the plate whenthe plate is alternately positive. When the plate 52 is positive therewill be current flow to the cathode 46 and condenser 42 will becomecharged. On the next half cycle, when the plate 52 becomes negative, thetube 44 will be non-conducting but the plate 56 will be positive andthere will be impressed on the terminals 66 the voltage of the condenser42 from the previous half cycle plus the voltage of the instant halfcycle which is rendering the plate 56 positive. This results in avoltage at 66 which is literally double that at the terminals 31, thisvoltage charging the condenser 64. During the next half cycle,corresponding to the first referred half cycle, the tube 44 is againconductive to charge the condenser 42, whereas the condenser 64 bolstersthe voltage at 66 by then discharging into the load connected thereto.In this manner a pulsating DC. voltage of approximately twice thevoltage at 31 is sustained at 66.

In view of the fact that various parts of my system are subjected toextremely high electrical tensions by virtue of the operating voltagesinvolved, it becomes essential to minimize the corona effect that wouldotherwise exist. With this aim in mind, I mount the system diagrammed inFigure 3 on a Lucite or Plexiglas chassis pictured in Figures 1 and 2,this chassis being designated generally by the letter C. Not all of theelements of Figure 3 are included, only the salient ones beingindicated, in Figures 1 and 2 in order to keep these two views as simpleas possible.

The tubes 44 and 54 are shown with plate terminals 68 and 70,respectively, and since these terminals 68 and 70 are alternately atwidely different potentials, the tubes 44 and 54 are inverted withrespect to each other. A partition 72 of Lucite or Plexiglas isinterposed between the tubes 44, 54 and this partition is provided withoppositely extending lateral shelves 74 and 76 upon which the bases ofthe tubes 44 and 54 are aifixed. Another partition 78 efiectivelyseparates the nearest tube, which is 54, from the high potential coil 30which is inductively coupled to the plate coil 22, the two coils beingcircumscribed about an insulating cylindrical form 80 which depends fromthe top 82 of the chassis C. Inasmuch as the tube 10 and the iron corecoil 36 are at relatively low potentials, they may be exposed externallyof the chassis in the manner shown.

In conclusion, it will be appreciated that this invention takescognizance of all of the important details which are necessary toproduce a workable system of the class described. It should bereiterated, however, that the various values specified throughout thisspecification are only suggestive and that others may be substituted inlieu thereof, although the ones mentioned have proved very satisfactoryin actual tests. Therefore, any limitations imposed upon the scope ofthis invention should be governed solely by the breadth of the appendedclaims and the reasonable equivalents thereof.

I claim:

1. A voltage multiplier system comprising an electronic tube including aplate circuit, cathode circuit and at least one grid element circuit,means in circuit with said plate and cathode for producing a platevoltage having a resonant frequency, said means including in circuittherewith a low inductance parallel resonant coil,

battery means connected to said low inductance coil, an oppositely woundhigh inductance resonant coil inductably coupled electromagnetically andelectrostatically to said low inductance coil and having one end thereofconnected to said one grid element circuit, combined inductive,capacitive and resistive means connected with the said one end of thehigh inductance resonant coil and decoupling the alternating oscillationof the grid, a condenser connected to the other end of said highinductance resonant coil, and parallel output circuit means connectingwith said condenser, said parallel circuit means including a rectifierin one leg thereof, and an oppositely disposed rectifier and condenserin the other leg.

2. The system described in claim 1 in which said high inductance coilproduces a secondary voltage in the approximate ratio of 75:1 to saidlow inductance coil.

3. In an alternating oscillator circuit for use in a voltage multipliersystem, an electronic tube including a plate circuit, cathode circuitand at least one grid circuit element, a direct current potential meansin circuit with said plate for producing an alternating oscillatoryplate voltage frequency, said means including in circuit therewith a lowinductance resonant coil, a high inductance resonant coil inductivelycoupled to said low inductance resonant coil and having one end thereofconnected to said one grid element, and shunt reactance means includinga coil equipped with a powdered iron core in circuit with said highinductance coil, said one grid element and said cathode circuit.

4. In a voltage multiplication system the method of obtaining stablevoltage value and producing a uniformly usable current comprising thesteps of changing the impedance of grid and controlling grid bias byregulation of amplitude of alternating oscillation, adjusting a resonantplate circuit, inductively feeding back the resonant adjusted platecircuit into an output circuit, and adjusting the excitation voltage ofthe feed back to maintain a bias relationship to plate circuit whichhalves the current on doubling the voltage.

5. In a voltage multiplication system the method of obtaining stablevoltage value and producing a uniformly usable current comprising thesteps of changing the impedance of grid and controlling grid bias byregulation of the alternating oscillation of amplitude at the controlgrid, adjusting a resonant plate circuit, inductively feeding back theresonant adjusted plate circuit into an output circuit, and adjustingthe excitation voltage of the feed back to maintain a bias relationshipto plate circuit which halves the current on doubling the voltage.

6. In a voltage multipler system for supplying stabilized output directcurrent voltage from a source of alternating current a circuitcomprising a pair of input alternating current terminals, an oscillatorcircuit including an electronic tube having a plate and plate circuit, acathode and cathode circuit, screen grid and screen grid circuit andcontrol grid and grid circuit, B-battery circuit means having a negativeside connected to a common ground of the multipler and the cathode ofthe alternating current generator and the positive side connected tosaid screen grid circuit and to said plate circuit, a resonant circuitconnecting said battery with said plate including a decouplingcomponent, a plate coil and a variable high capacitance condenser inparallel with said plate coil, the said screen grid element by-passedthrough a condenser to ground and connected to the positive side of saiddirect current voltage supply circuit, a resistor in the connectionbetween said screen grid and the said positive side of said directcurrent supply circuit, a plate return lead through a condenser toground, and an oppositely wound step up transformer coil and transformercoil circuit inductively coupled to said plate coil having one endconnected to said control grid and the opposite high impedance endconnected to one of said alternating current terminals, a control gridcircuit including a variable inductance, grid leak and grid condenserconnected to cathode having no tuning frequency relationship and saidvariable inductive coil uncoupled electromagnetically andelectrostatically to said plate coil and said oppositely Wound step-uptransformer coil.

References Cited in the file of this patent UNITED STATES PATENTS1,738,346 Barton Dec. 3, 1929 1,892,146 Harshberger Dec. 27, 19322,019,625 OBrien Nov. 5, 1935 2,172,962 Montgomery Sept. 12, 19392,212,202 Faudell et al Aug. 20, 1940 2,292,835 Hepp Aug. 11, 19422,374,781 Schade May 1, 1945 2,493,044 Thorne Jan. 3, 1950 2,568,484Cage Sept. 18, 1951 2,568,485 Cage Sept. 18, 1951 2,588,777 ThompsonMar. 11, 1952 2,596,623 Slooten May 13, 1952 2,659,854 Wengel Nov. 17,1953

